Which is why, when Razmir returns to his demiplane, he'll find a Gate to Hell (the arcane version, cast via Hell-provided scroll) open in it, with high-level Chelish wizards and fighters streaming through.

(They expected that Razmir himself had a Clone, which Aspexia Rugatonn stole via Miracle and destroyed before the attack began, but not that any of his minions who aren't even eighth circle did. Doesn't matter. They have everything they need anyway.)

"Streaming" is not, perhaps, quite the right verb, since the first group to attack were hit by Overwhelming Presence (which, to be fair, they Mind Blanked their way out of) and they and the rest have all been set upon by kytons, inevitables, constructs, Razmir's own undead, et cetera, et cetera, but it will nonetheless do to emphasize that holy shit there's a lot of them. The inevitable in charge of pressing the Freak Out Button to engage all the horrifically lethal traps and wake all the slumbering monsters did that, and is now basking in the warm glow of a mission successfully accomplished.

But, unfortunately, the location the Gate opens is the Teleport Trap in the Forbiddance, which is also the location Plane Shifts to the plane go.

Quickened Circle of Death centered on him, fly 40 feet towards safety while casting Extended Time Stop?

He won't get the chance.

Time Stop.

(Via Hell-provided scroll, as before. Hell is actually being helpful for once.)

Given that they had the action readied to cast the moment they saw him, they probably win the initiative roll on this one.

Antimagic Field covering Razmir, and there's already a fighter ready to whack him into unconsciousness the moment the Time Stop expires.

Razmir is the most powerful wizard in Avistan, plausibly the most powerful wizard in the world (though Nefreti Clapati would disagree.) He bears artifacts that render him almost impervious to harm, deflecting blades and spells with equal ease; his magic renders him immune to nearly any enchantment. He can see through the eyes and speak through the mouth of any mask of his, anywhere in the world, and stop time, tear open gates between planes, and kill absolutely every living thing near him with a single spell. 

In an antimagic field, he's just a frail old man.

They begin to strip him of his magic items, starting with those that enhance his Constitution, and then drag him back through the Gate, taking it down as his guards close in.

(Devils can kill any that tried to follow them through, at much lower intervention cost than if they were doing that outside Hell.)

They finish stripping him of his magic items and Dispelling his buffs.

Malediction.

She has it twice, and several scrolls besides, but Razmir is unconscious, stripped of all his buffs and magic items, and not very Wise, and she is as powerful as him when he isn't any of those things. She only needs it once.

Destruction.

And Razmir, living goddamn god of Razmiran, wakes up in one of his clones in its own private demiplane that is only accessible via rod which is only accessible via his gloves which can only be equipped by humans of pure Thassilonian blood, and guess what there aren't any others, because screw you, Aspexia Rugatonn.

Meanwhile, Eike wasn't the only Razmiran priest Cheliax hit. They were, in fact, able to learn that Razmir was probably at First Step that day, with the result that there is now a different, and much larger (not limited by the Gate), though generally lower-level, Chelish army surrounding the fortress, itself surrounding Remek Czaszar's army of undead.

Remek Czaszar feels that the possibility of effectively taking unified action to murder Razmir has passed, and it is time to, instead, DEPART. He does this at around the same time the average member of the Whispering Way comes to the same conclusion, and only the vast swarms of expendable undead that nobody cares in the slightest about evacuating are turning what would ordinarily be a complete rout into the sort of retreat in which people bother to use their full teleport capacity for their allies.

Well, some people.

Well, Remek Czaszar.

The massive swarms of expendable undead are still a problem, though! Especially since all the undead are Evil and many are Lawful! Valharuts tearing them apart with their spiked hooks and Order's Wrath spells and sacristans with their cursed chains are still hard-pressed, even if their inevitable victory is not in doubt, when an entire Chelish army appears outside. Still, however many defenders of First Step have rushed to its heart to oppose the Whispering Way, there are still others manning the defenses, who will not yield to Chelish armies without a fight (and have very good defensive prospects, should a fight begin.)

... One of the very junior priests who wasn't rushed to the battle-front and didn't get disintegrated in the ritual will, pretending he is not so junior, ride out under a flag of truce (they're lawful, it's safe, they're lawful, it's safe) to haughtily and with offense ask them why they're here when Razmiran and Cheliax are fellow Lawful Evil allies against the forces of Galt?

Yeah...'alliance' wasn't exactly the way they saw it. They tolerated Razmir, because he was useful, and Lawful enough to deal with, but Asmodeus has decreed that Razmir's blasphemy against the Prince of Hell ends today. They will mercifully spare the lives of the other blasphemers if they will hand over their false god.

... - Razmir isn't here right now!

Is he willing to swear this under Zone of Truth?

(buy time buy time buy time) - sure, if they'll swear an oath that that's the spell they're casting and that they aren't doing any others.

Sure.

... He swears that he does not know that Razmir is in First Step right now?

A moment later this is obviated by a Sending from Aspexia Rugatonn.

"We have word from our other forces that your false god is dead and in Hell." We Lawfully swear it, etc etc.

(This is true, to the best of their knowledge. The Malediction did take.)

This is impossible.

No, really, it's impossible; Razmir is a god and cannot die, they all know that. "Your commanders have lied to you! The Living God cannot be slain!"

Lol.

We're just gonna leave now, then. Have a nice day.

It will be a hard-fought battle, but, eventually, First Step can defeat the remaining expendable undead.

Of course, while that's going on, other things are also happening.